Sorry, I must respectfully disagree;I would go for the paint....many reasons. Those kits are not an easy install to get them on straight. They don't come off easily if you change your mind (they'll break for sure). The adhesive is a bear to remove..... The individual sections can warp in the sun, or simply with age. You'll probably be unable to buy a single piece if one goes bad...... or if you can find one, the colors will be slightly off.
With paint, you can do a touch-up, or go back to stock, or some other color for the price of a can of paint.
OK, now that I'm awake!!^^^^^I'm sure the quality of various kits is not the same. My experience has been with factory accessory kits, which you would think would be high-quality. When the pieces are new, they are relatively flexible.....give them a few years and they're hard as a rock, and start cracking and peeling. The adhesive will harden quickly, and after a while you'll need a knife to remove it.
I can't tell you how many cars with these kits I've seen......with missing or cracked sections, that looked like crap after a few years. YMMV